Limit-stop for elevators



2 Sheets-Sheet 1.

(No Model.)

T. W. HEERMANS. LIMIT STOP FOR ELEVATORS.

Patented Aug. 9, 1892.

No Model.) 2 sheets Sheet 2.

T. W. HEERMANS. LIMIT STOP FOR ELEVATORS.

No. 480,583. Patented Aug. 9, 1892.

to arod P extending parallel'to the girder D.

' UNITED STATES PATENT ()FFICE.-

THADDEUS W. HEERMANS, OF OHIOAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE NATIONAL COMPANY, OF ILLINOIS.

LIM lT-STOP FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 480,583, dated August 9, 1892. Application filed June 26, 1891. Serial No; 397,657. (No model.)

T0 at whom it may concern.-

Be it known that I, THADDEUS W. HEER- MANS, residing at Chicago, in the county of Cook, in the State of Illinois, have invented certain new and useful Improvements in Limit-Stops for Elevators, of which the following is a specification.

My invention relates more especially to hydraulic elevators in which as ordinarily constructed the car passes over the entire length of its travel at a single stroke of the elevatorpiston.

My device is designed to shut off the flow of fluid to or from the elevator-cylinder as the piston approaches the limit of its travel at either end of the cylinder.

- In the drawings, Figure 1 is a side elevation of the elevator-cylinder and a portion of its attachments sufficient to illustrate my invention. Fig. 2 is a plan view on a larger scale of the devices forming the limit-stop, and Fig. 3 is a side elevation of the same.

A, Fig. 1, is the elevator-cylinder.

B represents the movable sheaves connected to the piston-rod, and 0 represents the fixed sheaves mounted upon a girder D, extending to the cylinder. Said girder D serves as a guide for the cross-head E, in which the sheaves B are journaled.

F is the control-valve by which the admission and exhaust of fluid through the pipe H to and from the cylinder A is governed. A valve G is inserted in the passage-way between the control-valve F and the cylinder A. The valve G is connected to a leverI by a rod J and rock-shaft K. The lever I is supported by a stud L, fastened to the girder D, and is provided with arms M N, projecting on each side of its fulcrum. A slide 0 is likewise supported upon the stud L and is connected Upon the rod P are adjustable stops R B. An arm S is fastened to the cross-head E. 'Its outer end projects between the stops R R, being provided with an opening through which the rod P passes. Secured to the lever I is an arm T, at the outer end of which is aweight U. Upon the slide 0 are two projections V V, which make contact with the opposite faces of the arms M N, respectively.

In order to diminish friction, the projections V V are given the form of rollers mounted upon studs.

The operation of the device is as follows: In the position shown in Fig. 1 the weight U has moved to its lowest possible point, the arms M N being in simultaneous contact with the projections V V, respectively. In this position the valve H is open. The adjustable stops R R are so set upon the rod P that the arm S, attached to the cross-head, comes in contact with one or the other'stop just as the piston approaches the limit of its movement at either end of the cylinder. The contact of the arm S with either stop R moves the rod P longitudinally. The effect of this movement is to push the slide 0 to the right or left, as seen in Fig. 1, the movement in either direction raising the weight U and closing the valve H through the action of the projection V on the arm N, or V upon the arm M. The flow of fluid is thus gradually stopped or checked so that the piston comes to rest. The valve H is not made perfectly tight, and a certain leakagemay take place through it. This permits the reversal of the movement of the piston, notwithstanding the closure of the valve H when the position of the controlvalve is changed, the speed of such movement being dependent upon the amount of leakage through the valve H until the reverse travel of the piston is sufficient to permit the reopening of said valve by the action of the Weight U.

What I claim as new, and desire to secure by Letters Patent, is as follows:

1. The combination, in a limit-stop for elevators, of a valve in the passage between the control-valve and the cylinder, a lever connected to said valve, having arms projecting each side of the fulcrum, a slide having projections engaging with said arms on their 0pposite sides, and a rod connected to said slide, having stops thereon engaging with a moving part connected to the elevator-piston, su bstantially as described.

2. The combination, in a limit-stop for elevators, of a valve in the passage between the control-valve and the cylinder, a lever connected to said valve, having arms projecting oppositely-proj ectin g arms M N, a slide 0, sn pported upon said stud L and having projections V V engaging with opposite sides of the arms M N, respectively, a rod P, having stops R R thereon and connected to the slide 0 and the arm S, secured to the cross-head E and operating between said stops R R, and the weight stantially as described.

THADDEUS W. HEERMANS. Witnesses:

ELSIE NEMETT, Tom) MASON.

U, adapted to maintain the arms M N in con- 20 I tact with the studsv V V, respectively, sub- 

